sim/ppc/hw_nvram.c

   1 /*  This file is part of the program psim.
   2
   3     Copyright (C) 1994-1996, Andrew Cagney <cagney@highland.com.au>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18
  19     */
  20
  21
  22 #ifndef _HW_NVRAM_C_
  23 #define _HW_NVRAM_C_
  24
  25 #ifndef STATIC_INLINE_HW_NVRAM
  26 #define STATIC_INLINE_HW_NVRAM STATIC_INLINE
  27 #endif
  28
  29 #include "device_table.h"
  30
  31 #ifdef HAVE_TIME_H
  32 #include <time.h>
  33 #endif
  34
  35 #ifdef HAVE_STRING_H
  36 #include <string.h>
  37 #else
  38 #ifdef HAVE_STRINGS_H
  39 #include <strings.h>
  40 #endif
  41 #endif
  42
  43 /* DEVICE
  44
  45
  46    nvram - non-volatile memory with clock
  47
  48
  49    DESCRIPTION
  50
  51
  52    This device implements a small byte addressable non-volatile
  53    memory.  The top 8 bytes of this memory include a real-time clock.
  54
  55
  56    PROPERTIES
  57
  58
  59    reg = <address> <size> (required)
  60
  61    Specify the address/size of this device within its parents address
  62    space.
  63
  64
  65    timezone = <integer> (optional)
  66
  67    Adjustment to the hosts current GMT (in seconds) that should be
  68    applied when updating the NVRAM's clock.  If no timezone is
  69    specified, zero (GMT or UCT) is assumed.
  70
  71
  72    */
  73
  74 typedef struct _hw_nvram_device {
  75   unsigned8 *memory;
  76   unsigned sizeof_memory;
  77 #ifdef HAVE_TIME_H
  78   time_t host_time;
  79 #else
  80   long host_time;
  81 #endif
  82   unsigned timezone;
  83   /* useful */
  84   unsigned addr_year;
  85   unsigned addr_month;
  86   unsigned addr_date;
  87   unsigned addr_day;
  88   unsigned addr_hour;
  89   unsigned addr_minutes;
  90   unsigned addr_seconds;
  91   unsigned addr_control;
  92 } hw_nvram_device;
  93
  94 static void *
  95 hw_nvram_create(const char *name,
  96                 const device_unit *unit_address,
  97                 const char *args)
  98 {
  99   hw_nvram_device *nvram = ZALLOC(hw_nvram_device);
 100   return nvram;
 101 }
 102
 103 typedef struct _hw_nvram_reg_spec {
 104   unsigned32 base;
 105   unsigned32 size;
 106 } hw_nvram_reg_spec;
 107
 108 static void
 109 hw_nvram_init_address(device *me)
 110 {
 111   hw_nvram_device *nvram = (hw_nvram_device*)device_data(me);
 112
 113   /* use the generic init code to attach this device to its parent bus */
 114   generic_device_init_address(me);
 115
 116   /* find the first non zero reg property and use that as the device
 117      size */
 118   if (nvram->sizeof_memory == 0) {
 119     reg_property_spec reg;
 120     int reg_nr;
 121     for (reg_nr = 0;
 122          device_find_reg_array_property(me, "reg", reg_nr, &reg);
 123          reg_nr++) {
 124       unsigned attach_size;
 125       if (device_size_to_attach_size(device_parent(me),
 126                                      &reg.size, &attach_size,
 127                                      me)) {
 128         nvram->sizeof_memory = attach_size;
 129         break;
 130       }
 131     }
 132     if (nvram->sizeof_memory == 0)
 133       device_error(me, "reg property must contain a non-zero phys-addr:size tupple");
 134     if (nvram->sizeof_memory < 8)
 135       device_error(me, "NVRAM must be at least 8 bytes in size");
 136   }
 137
 138   /* initialize the hw_nvram */
 139   if (nvram->memory == NULL) {
 140     nvram->memory = zalloc(nvram->sizeof_memory);
 141   }
 142   else
 143     memset(nvram->memory, nvram->sizeof_memory, 0);
 144
 145   if (device_find_property(me, "timezone") == NULL)
 146     nvram->timezone = 0;
 147   else
 148     nvram->timezone = device_find_integer_property(me, "timezone");
 149
 150   nvram->addr_year = nvram->sizeof_memory - 1;
 151   nvram->addr_month = nvram->sizeof_memory - 2;
 152   nvram->addr_date = nvram->sizeof_memory - 3;
 153   nvram->addr_day = nvram->sizeof_memory - 4;
 154   nvram->addr_hour = nvram->sizeof_memory - 5;
 155   nvram->addr_minutes = nvram->sizeof_memory - 6;
 156   nvram->addr_seconds = nvram->sizeof_memory - 7;
 157   nvram->addr_control = nvram->sizeof_memory - 8;
 158
 159 }
 160
 161 static int
 162 hw_nvram_bcd(int val)
 163 {
 164   val = val % 100;
 165   if (val < 0)
 166     val += 100;
 167   return ((val / 10) << 4) + (val % 10);
 168 }
 169
 170
 171 /* If reached an update interval and allowed, update the clock within
 172    the hw_nvram.  While this function could be implemented using events
 173    it isn't on the assumption that the HW_NVRAM will hardly ever be
 174    referenced and hence there is little need in keeping the clock
 175    continually up-to-date */
 176
 177 static void
 178 hw_nvram_update_clock(hw_nvram_device *nvram,
 179                       cpu *processor)
 180 {
 181 #ifdef HAVE_TIME_H
 182   if (!(nvram->memory[nvram->addr_control] & 0xc0)) {
 183     time_t host_time = time(NULL);
 184     if (nvram->host_time != host_time) {
 185       time_t nvtime = host_time + nvram->timezone;
 186       struct tm *clock = gmtime(&nvtime);
 187       nvram->host_time = host_time;
 188       nvram->memory[nvram->addr_year] = hw_nvram_bcd(clock->tm_year);
 189       nvram->memory[nvram->addr_month] = hw_nvram_bcd(clock->tm_mon + 1);
 190       nvram->memory[nvram->addr_date] = hw_nvram_bcd(clock->tm_mday);
 191       nvram->memory[nvram->addr_day] = hw_nvram_bcd(clock->tm_wday + 1);
 192       nvram->memory[nvram->addr_hour] = hw_nvram_bcd(clock->tm_hour);
 193       nvram->memory[nvram->addr_minutes] = hw_nvram_bcd(clock->tm_min);
 194       nvram->memory[nvram->addr_seconds] = hw_nvram_bcd(clock->tm_sec);
 195     }
 196   }
 197 #else
 198   error("fixme - where do I find out GMT\n");
 199 #endif
 200 }
 201
 202 static void
 203 hw_nvram_set_clock(hw_nvram_device *nvram, cpu *processor)
 204 {
 205   error ("fixme - how do I set the localtime\n");
 206 }
 207
 208 static unsigned
 209 hw_nvram_io_read_buffer(device *me,
 210                         void *dest,
 211                         int space,
 212                         unsigned_word addr,
 213                         unsigned nr_bytes,
 214                         cpu *processor,
 215                         unsigned_word cia)
 216 {
 217   int i;
 218   hw_nvram_device *nvram = (hw_nvram_device*)device_data(me);
 219   for (i = 0; i < nr_bytes; i++) {
 220     unsigned address = (addr + i) % nvram->sizeof_memory;
 221     unsigned8 data = nvram->memory[address];
 222     hw_nvram_update_clock(nvram, processor);
 223     ((unsigned8*)dest)[i] = data;
 224   }
 225   return nr_bytes;
 226 }
 227
 228 static unsigned
 229 hw_nvram_io_write_buffer(device *me,
 230                          const void *source,
 231                          int space,
 232                          unsigned_word addr,
 233                          unsigned nr_bytes,
 234                          cpu *processor,
 235                          unsigned_word cia)
 236 {
 237   int i;
 238   hw_nvram_device *nvram = (hw_nvram_device*)device_data(me);
 239   for (i = 0; i < nr_bytes; i++) {
 240     unsigned address = (addr + i) % nvram->sizeof_memory;
 241     unsigned8 data = ((unsigned8*)source)[i];
 242     if (address == nvram->addr_control
 243         && (data & 0x80) == 0
 244         && (nvram->memory[address] & 0x80) == 0x80)
 245       hw_nvram_set_clock(nvram, processor);
 246     else
 247       hw_nvram_update_clock(nvram, processor);
 248     nvram->memory[address] = data;
 249   }
 250   return nr_bytes;
 251 }
 252
 253 static device_callbacks const hw_nvram_callbacks = {
 254   { hw_nvram_init_address, },
 255   { NULL, }, /* address */
 256   { hw_nvram_io_read_buffer, hw_nvram_io_write_buffer }, /* IO */
 257 };
 258
 259 const device_descriptor hw_nvram_device_descriptor[] = {
 260   { "nvram", hw_nvram_create, &hw_nvram_callbacks },
 261   { NULL },
 262 };
 263
 264 #endif /* _HW_NVRAM_C_ */